• KSBB Journal
• /
• v.31 no.2
• /
• pp.120-125
• /
• 2016

Two-dimensional cultivation is typically used for cell growth, but the method reduces the characteristics of chondrocytes and stem cells, and limits culture area. Therefore, development of three-dimensional culture method is needed to mimic in vivo environment, improve quality of cells and scale-up efficiently. Improving proliferation and chondrogenesis is available by co-culture of chondrocytes and mesenchymal stem cells (MSCs) that leads to interaction between two kinds of cells. However, the co-culture has problems that permeability of sphere diminishes as aggregate size increased and ratio of two kinds of cells composing each spheres is different. In this work, co-cultivation method using controlled sphere composed of chondrocytes and MSCs was established and enhanced chondrogenesis. Periosteum-derived progenitor cells (PDPCs) that are appropriate for cell therapy source of articular cartilage were used as MSCs. Controlled spheres were formed in the hanging-drop plates and shifted for being induced chondrogenesis in 35-mm non-adhesive culture dishes at a rotation rate of 60 rpm. After inducing chondrogenesis, gene expressions related with chondrogenesis were found to be improved and it was apparent that the utilization of controlled spheres promoted chondrogenesis. As a result, available numbers of cells per unit area were increased and chondrogenic differentiation ability was improved compared to typical two-dimensional culture. This approach shows the potential in cartilage regeneration as it can provide sufficient numbers of chondrocytes.

• Journal of the Korean Home Economics Association
• /
• v.39 no.8
• /
• pp.137-154
• /
• 2001

This study was made to draft the tight fitting bodice pattern which horizontal and perpendicular stands are to be lightly set, with the consideration of characteristics of body shape in design of clothes. Measurement of body was conducted on 53 women in twenties, and observation was made on surface development pattern by adhesive tape addition method and gypsum method on three standard objects. In the study, bodice pattern was completed by using already made Somato- measurer, compared with existing bodice pattern, and the results are as follows. The result of the correlation analysis by body measurement shows that chest circumference has a relation to B$.$P-front neck point, side neck point, shoulder point, front interscye breadth point, and the item in spine scapulae point has relation to the item of back neck line, and front & back horizontal values. The degree of shoulder slant, width of armhole and of its depth, the amount of breast, back space, back length were shown to be directly measured from the body. In surface development pattern, tight-fit bodice pattern necessary to the breast volume and back space were shown to be investigated and these volume have to be given in setting up basic line for clothes design together with body measurement value. The result of sensory evaluation for appearance test on fitness shows higher value of research bodice including line of shoulder line, front and back interscye breadth, chest circumference, waist circumference, armhole circumference and of its depth, compared with the research bodice in most items. The result of this study is seen showing high effectiveness for the basic data to design the ready-made dress of high sensitivity of high value added tat.

• Journal of Adhesion and Interface
• /
• v.5 no.2
• /
• pp.22-36
• /
• 2004

Several in-situ testing methods of adhesively bonded joints under static short-time tensile loading are critically analyzed in terms of experimental procedure and data evaluation. Due to its rather homogeneous stress state across the glue line, the tensile-shear test with thick single-lap specimens, according to ISO 11003-2, has become the most important test process for the determination of realistic materials parameters. This basic method, which was improved in both, the experimental part by stepped adherends and easily attachable extensometers and the evaluation procedure by numeric substrate deformation correction and test simulation based on the finite element method (FEM), is therefore demonstrated by application to several kinds of adhesives and metallic adherends. Multi-axial load decreases the strength of a joint. This effect, which is illustrated by an experimental comparison, impedes the derivation of realistic mechanical characteristics from measured force-displacement curves. It is shown by numeric modeling that tensile-shear tests with thin plate substrates according to ISO 4587, which are widely used for quick industrial quality assurance, reveal an inhomogeneous stress state, especially because of relatively large adherend deformation. Complete experimental determination of the elastic properties of bonded joints requires independent measurement of at least two characteristics. As the thick-adherend tensile-shear test directly yields the shear modulus, the tensile butt-joint test according to ISO 6922 represents the most obvious complement of the test programme. Thus, validity of analytical correction formulae proposed in literature for the derivation of realistic materials characteristics is verified by numeric simulation. Moreover, the influence of the substrate deformation is examined and a FEM correction method introduced.

• Journal of Information Processing Systems
• /
• v.14 no.4
• /
• pp.1049-1061
• /
• 2018

As mobile devices such as smartphones and tablet PCs become more popular, users are becoming accustomed to consuming a massive amount of multimedia content every day without time or space limitations. From the industry, the need for user satisfaction investigation has consequently emerged. Conventional methods to investigate user satisfaction usually employ user feedback surveys or interviews, which are considered manual, subjective, and inefficient. Therefore, the authors focus on a more objective method of investigating users' brainwaves to measure how much they enjoy their content. Particularly for multimedia content, it is natural that users will be immersed in the played content if they are satisfied with it. In this paper, the authors propose a method of using a portable and dry electroencephalogram (EEG) sensor device to overcome the limitations of the existing conventional methods and to further advance existing EEG-based studies. The proposed method uses a portable EEG sensor device that has a small, dry (i.e., not wet or adhesive), and simple sensor using a single channel, because the authors assume mobile device environments where users consider the features of portability and usability to be important. This paper presents how to measure attention, gauge and compute a score of user's content immersion level after addressing some technical details related to adopting the portable EEG sensor device. Lastly, via an experiment, the authors verified a meaningful correlation between the computed scores and the actual user satisfaction scores.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.31 no.4
• /
• pp.231-237
• /
• 2018

In this study, two important requirements for the home production of a robot to detect and remove improvised explosive devices (IEDs) are presented in terms of the total cost for robot system development and the performance improvement of the mine detection technology. Firstly, cost analyses were performed in order to provide a reasonable solution following an engineering estimate method. As a result, the total cost for a mass production system without the mine detection system was estimated to be approximately 396 million won. For the case including the mine detection system, the total cost was estimated to be approximately 411 million won, in which labor costs and overhead charges were slightly increased and the material costs for the mine detection system were negligible. Secondly, a method for fabricating the carbon nanotube (CNT) based gas detection sensor was studied. The detection electrodes were formed by a photolithography process using a photosensitive CNT paste. As a result, this method was shown to be a scalable and expandable technology for producing excellent mine detection sensors. In particular, it was found that surface treatments by using adhesive taping or ion beam bombardment methods are effective for exposing the CNTs to the ambient air environment. Fowler-Nordheim (F-N) plots were obtained from the electron-emission characteristics of the surface treated CNT paste. The F-N plot suggests that sufficient electrons are available for transport between CNT surfaces and chemical molecules, which will make an effective chemiresistive sensor for the advanced IED detection system.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.45 no.2
• /
• pp.105-116
• /
• 2019

Oil adsorption during hair or body washing is responsible for the hair conditioning. In this study, we established a method to extract oil from a substrate, and to determine amount of adsorbed oil upon substrate using a conventional absorption spectroscopy. We controlled the mole fraction of a surfactant in a mixture of anionic and amphoteric surfactants because that it induces the coacervate that regulates amount of adsorbed oil through the alteration of oil viscosity. Based on this, we established the optimized condition for adsorption and extraction for oil. UV absorbance were employed to estimate the amount of adsorbed oil using optical absorbance after extraction via adsorption. The estimation was confirmed by comparing with a mass analysis in HPLC and an adhesive energy in AFM. It has been proved that this method can be applied to all cases of oil adsorption from the results with various cationic polymers and a complex system of the polymers which regulate the oil adsorption.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.3
• /
• pp.178-184
• /
• 2002

High-throughput screening has become a popular method used to identify new “leads”for potentially therapeutic compounds. Further screening of these lead compounds is typically done with secondary assays which may utilize living, functioning cells as screening tools. A problem (or benefit) with these cell-based assays is that living cells are very sensitive to their environment. We have been interested in the process of stem cell migration and how it relates to the cellular therapy of bone marrow transplantation. In this study we describe a secondary, cell-based assay for screening the effects of various in-vitro conditions on Immature Hematopoietic Cell (IHC) migration. Our results have revealed many subtle factors, such as the cell's adhesive characteristics, or the effect of a culture's growth phase, that need to be accounted for in a screening protocol. Finally, we show that exponentially glowing KG1a cells (a human IHC cell line) were 10 times more motile than those in the lag or stationary phases. These data strongly suggest that KG1a cells secrete a chemokinetic factor during the exponential growth phase of a culture.

• Animal cells and systems
• /
• v.7 no.4
• /
• pp.331-335
• /
• 2003

Vertebrates with different habitats have different proportions of visual cells, with the rod cells responding to scotopic vision and the cone cells responding to photopic and color vision in their retinas. The present work studied whether the kinds and arrangement patterns of the cone cells and interlocking morphology of the lens were related to the kind of preys and habitats in the genus Zacco. The retinas were observed by a light microscopy using H-E staining method and the interlocking formula of the lens fibers were investigated by a scanning electron microscopy. The interlocking formula of the lens fibers of Z. temmincki is an ' anchor and socket ' connection, and that of Z. platypus is a ' ball and socket ' connection. The cone cells of Z. platypus and Z. temmincki constituted compacted mosaic patterns of row type. Away from the center, the double and single cone cells gradually increased in diameter. Zacco temmincki had identical double cone cells and Z. platypus had non-identical double and single cone cells. The eyes of Z. temminckifeeding on a moving aquatic insects in relative limpid water and swift current of mid and upper stream have better resolution than that of Z. platypus feeding on mainly adhesive algae and some aquatic insects in slightly turbid water of mid stream.

• Journal of the Microelectronics and Packaging Society
• /
• v.25 no.2
• /
• pp.9-17
• /
• 2018

Aluminum (Al) and its alloys have been used widely in a variety of industries such as structural, electronic, aerospace, and particularly automotive industries due to their lightweight characteristic, outstanding ductility, formability, high oxidation and corrosion resistance, and high thermal and electrical conductivity. Al have different kinds of alloys according to the various additional elements system and they should be selected properly depending on their effectiveness and suitability for their particular purpose. The major elements for Al alloys are silicon (Si), magnesium (Mg), manganese (Mn), copper (Cu), and zinc (Zn). In order for Al alloys to use for each industry, it is necessary to study of Al to Al joining and/or the Al to dissimilar materials joining to combine the individual parts into one. Many studies on joining technologies about Al to Al and Al to dissimilar materials have been performed such as press joining, bolted joint, welding, soldering, riveting, adhesive bonding, and brazing. This study reviews a variety of Al alloys and their joining method including its principles and properties with recent trends.

• Journal of Information Technology Services
• /
• v.17 no.3
• /
• pp.53-61
• /
• 2018

In this paper, we propose a car sealing monitoring system combined with ICT Technology. The automobile sealer is an adhesive used to bond inner and outer panels of doors, hoods and trunks of an automobile body. The proposed car sealer monitoring system is a system that can accurately and automatically inspect the condition of the automobile sealer coating process in the general often factory production line where the lighting change is very severe. The sealer inspection module checks the state of the applied sealer using an area scan camera. The vision inspection algorithm is adaptive to various lighting environments to determine whether the sealer is defective or not. The captured images and test results are configured to send the task results to the task manager in real-time as a smartphone app. Vision inspection algorithms in the plant outdoors are very vulnerable to time-varying external light sources and by configuring a monitoring system based on smart mobile equipment, it is possible to perform production monitoring regardless of time and place. The applicability of this method was verified by applying it to an actual automotive sealer application process.